Core C: This program project focuses on understanding the determinants and consequences of changing patterns of functioning, morbidity, and mortality in aging populations in Africa. The research in this program requires valid, reliable, and comparable measures for an array of variables in diverse study sites and rigorous methods for analyzing key relationships between these variables. The overall goal of the Measures and Methods Core (Core C) is to serve as a fundamental resource to the program subprojects, the investigative team, and the scientific community, via a set of key functions, including: developing and disseminating a harmonized set of measurement instruments and protocols; developing the analytic basis for instrument testing and validation, in close collaboration with the Data Collection and Management Core (Core D); and providing a focal point and toolkit for standardized data analysis and synthesis of research findings, in a way that makes maximal use of all new and existing data sources available in the study sites. Toward this end, the Measures and Methods Core has three specific aims: 1. To develop a comprehensive set of instruments and protocols for valid, reliable and comparable measurement of functional health status, morbidity, risk factor exposures, and economic and social covariates of health. 2. To coordinate development and standardized application of core analytic tools to support specific inquiries and hypothesis tests in the research projects. 3. To develop and validate a parsimonious set of low-cost, interview-based measurement tools that can be deployed in the future for regular monitoring of selected outcomes through routine surveillance visits that occur between major survey rounds.